Transmission control



W INL Q E6 1%41-3. a E" UN TRANSMISSION CONTROL Filed Dec. 15, 1941 4Sheets-Sheet l Nov. 16, 1943. G. E. FL NN 2,334,402

TRANSMISSION CONTROL Filed Dec. 13, 1941 4 Sheets-Sheet 2 fizverzzfr'" 6607196 if Flzlnrz NOV. 16, FLlNN 2,334,402

TRANSMISSION CONTROL Filed Dec. 13, 1941 4 Sheets-Sheet 3' V flit/872%707196 E f 12.72.72,

G. E. FLENN 2,334,402

TRANSMISSION CONTROL Filed Dec. 15, 1941 4 Sheets-$heet 4' fig? George.5: FZL'nn Patented Nov. 16, 1943 TRAN SMIS SION CONTROL George E.Flinn, Muncie, Ind., assignor to Borg- Warner Corporation, Chicago,111., a corporation of Illinois Application December 13, 1941, SerialNo. 422,805

22 Claims.

This invention relates to transmissions and particularly to a controlmeans for a change speed transmission.

This invention is particularly well adapted for use with an automatic"transmission of the type described in a copending application of J. M.Simpson et al., Serial No. 403,196, filed July 19, 1941, and is in thenature of an improvement over the Simpson et a1. transmission.

In the above Simpson et al. application a combination countershaft typetransmission and planetary type transmission is disclosed with means forautomatically effecting shifts through the countershaft and planetarytransmissions in a coordinated manner to secure a. plurality of forwardspeed ratios. The two types of transmissions are so arranged that anintermediate shaft is required for connecting the two transmissionstogether, with automatically releasable clutching means, such as freewheeling clutches, for connecting the intermediate shaft to the drivingand driven shafts. Positively interengageable elements are provided foreffecting a change in ratio between the intermediate shaft and drivenshaft, the elements being dependent upon arelative reversal of directionof rotation in order to effect the engagement thereof. Since theintermediate shaft is automatically disene gaged from the drive anddriven shafts, it has a tendency to float with the driven shaft andthereby delay the establishment of the requisite change in direction ofrotation for engaging the V a positively interengageable elements.

The'solution to this problem previously proposed comprised reversing theconstruction of the interengageable elements so that they may be engagedwithout requiring a reversal in the direction of rotation of one of theelements.

Along with this construction automatic means were provided for delayingthe operation of the elements for a predetermined time interval toprevent undue clash. It is sometimes desirable, however, to acceleratethe shift rather than delay it, as for example, in an emergency where aquick get away is desired, and in such situations the constructiondisclosed in the prior Simpson et al. application would not besatisfactory.

The principal object of this invention is to provide a control devicefor positively interengageable elements which device may be operatedautomatically to accelerate the engagement of the elements.

A more specific object of this invention is to provide a means, in atransmission havinga floating shaft which controls the speed of one ofdescription of the schematically, a transmission of the type to two ormore interengageable elements, for rapidly decelerating the shaftautomatically in order to bring about a reversal in thedirection ofrotation' of the interengageable elements and thereby to facilitatetheir engagement.

Another object of this invention isto provide a two unit transmissionwherein a countershaft type transmission is employed as one of the unitsand an overdrive transmission is employed as the other unit, with aninter-connecting floating shaft and with automatically operated brakevmeans for the intermediate shaft .for slowing down and then reversingthe direction of rotation of the sun gear .in order to effect morerapidly a shift from direct drive through the overdrive transmission toan overdrive.

Another object of this invention is to provide a novel electro-magneticbrake for controlling the time of shifts of an overdrive transmission.

Still another object is to provide several modifications of anelectro-magnetic brake which would be suitable for the purpose intended.

These and other objects and features of this invention will becomeapparent from the following description when taken together with theaccompanying drawings in which:

Fig. 1 is a diagrammatic elevation in section of an automatictransmission showing the control means of this invention appliedthereto;

Fig. 2 is an enlarged section through the novel control mechanism;

Fig. 3 is a fragmentary front elevation taken along lines 3-3 of Fig. 2;

'Fig. 7 is a wiring diagram showing how this I invention may beconnected to operate with an overdrive transmission. I

Referring now to the drawings for a detailed invention, Fig. '1

which this invention is particularly adaptable. It is comprised of adrive shaft l0 which is driven by a prime mover such as an internalcombustion engine, a hydraulic coupling ll driven by drive shaft I0, afriction clutch l2 driven by coupling II and manually releasable by theusual clutch release lever l3, and an input shaft M which connects theclutch I2 to a countershaft-type unit A planetary type variable speedunit I 6 is driven from countershaft unit l5 by means of an intermediateshaft ll. The output or driven shaft of the planetary unit It is shownat l8.

shows gear 24 and a reversegear 25.

It should be noted at this point that in order for pawl 45 to engageslotted member 44, the

-latter must come to rest and in fact begin to possible a neutralcondition in the counter-shaft unit. When gear 26 is slid to the rightit engages an idler (not shown) which in turn meshes with'reverse gear25 and thereby establishes a reverse drive in intermediate shaft I1.

Meshing with second'speed gear 23 is a gear 21 which is loosely mountedon intermediate shaft I1. A slidable jaw clutch 28 is provided forconnecting gear 21 to intermediate shaft I1 to provide a second speeddrive through the countershaft unit. A second jaw clutch 29 serves toconnect gear 21 to gear I9 for direct drive. Said clutch 29 provides apositive two-way connection between the gears I9 and 21. Thus whenclutches 28 and .29 are engagedand sliding gear 26 is in the positionshown (neutral) a direct drive is established through countershaft unitI5.

In order that the engine may be used as a brake whilethe countershaftunit I5 is conditioned for second speed drive, a lock-up clutch 30 isprovided which substitutes a two-way drive between gear and countershaft2| for the overrunning clutch drive 22. When clutch 30 is disengaged,however, intermediate shaft I1 is not connected to drive shaft I4 andhence will not be decelerated with the engine.

Suitable levers are provided for operating thevarious clutches asfollows: lever .3I controls sliding gear 26, lever 32 controls jawclutch 28,

lever 33 controls second speed lock-up clutch 38 and lever 34 controlsdirect drive .clutch 29. Each of these levers may be manually operated,or, alternatively, may be operated automatically as described in theaforesaid Simpson et al. ap-

plication.

For purposes of illustration, planetary unit I6 is shown comprised of acommercially available overdrive unit such as is generally attached toThe overdrive is comprised of a planetary gear set having a ring gear35, a sun gear 36 and a plurality of planet pinions 31 meshing with sungear 36 and ring gear 35. Planet pinions 31 are mounted on a carrier 38which is connected directly to intermediate shaft I1 and is rotatabletherewith. Ring gear 35 is connected by means of a clutch 39 to drivenshaft I8. A direct drive between intermediate shaft I1 and driven shaftI8 is provided by means of a releasable clutch 40 which may be of thecam-and-roller type such that it is automatically releasable upon areversal of driving relations between the shafts. A lookup clutch M isprovided to prevent a release of clutch 48 when it is desired to coastagainst the engine. Clutch 39 is controlled by a lever and yokemechanism 42.

Sun gear 36 is connected to an automatically controlled brake 43. Saidbrake 43 is comprised of a slotted member 44 which is connected torotate with sungear 36 and a radially slidable rotate reversely, due tothe particular construction of the pawl as will be described hereinafterin connection with Fig. 4. Normally this slight reversal in thedirection of rotation of slotted member 44 is brought about by slowingdown the drive shaft I0 as for example by release of the acceleratorpedal. If the shift from direct drive to overdrive in planetary unit I6is to be effected while countershaft unit I5 is conditioned for secondspeed operation through overrunning clutch 22, releasing the acceleratorwill not necessarily cause intermediate shaft I1 to decelerate since thelatter is then disconnected from drive shaft I0 because of the freewheeling action of overruning clutch 22. Shaft I1 therefore will tend tofloat and rotate at a constantly decreasing speed, the rate ofdeceleration being much lower than the rate of deceleration of driveshaft I0. Under these conditions it would take much longer to effect anoverdrive than would be desirable. In the construction shown in theaforementioned Simpson et al. application this condition was alleviatedby changing the chamfer of the pawl so that. it could be engaged withthe slotted member before the latter came to rest. To avoid tooth clash,the radial inward movement of the pawl was delayed electrically for apredetermined time to give the slotted member a chance to slow down.This however, involved a change in the standard construction of theoverdrive and also involved the use of a time delay device, the actionof which was difficult to control accurately and which under certaincircumstances did not operate quickly enough to suit the drivers needs.

' In accordance with thepresent invention, a standard pawl and slottedmemberv construction is used, but an additional brake -mechanism' 41 isoperatively connected with intermediate shaft I1 to decrease the amountof time required to bring slotted member 44 to rest and to rotate it ina reverse direction. In the form shown, brake 41 is comprised of, afixed coil 48 surrounding intermediate shaft I1, and a disc-shapedarmature 49 likewise surrounding intermediate shaft the output shaft ofa standard transmission.

engageable with slotted member 44 to arrest the rotation of sun gear 36.

I will rotate together.

-magnet 46 are both controlled by a governor 69 I1, but splined to saidshaft I1 so that the two Brake 41 and electrowhich is driven from drivenshaft I8. It will be observed that if brake 41 is conditioned foroperation at the same time that solenoid 46 is conditioned to move pawl45 radially inward, shaft I1 will slow down carrier 38 and sun gear 36will therefore slow down at a still greater rate so that it will soonstop and begin to rotate in a reverse direction thereby bringing aboutthe conditions under which sun gear brake 43 may become effective.

Referring now to Figs. 2 and 4 for a detailed description of the sungear brake 43, the sun gear 36 is provided with a sleeve 5| to which issplined the slotted member 44. Said slotted member 44 is provided with ashoulder 62 on which is mounted frictlonally a balk ring 53, said balkring being provided with lugs 54 and 55 which are adapted to engage thesides of pawl 45. The lugs 54 and 56 are provided with shoulders 56 and51 respectively, which extend into the path of movement of pawl 45depending upon the direction of rotation of sun gear 36.

end 58 of pawl 45 is chamfered to prevent pawl The- 45 from engagingslotted member 44 while the latter is rotating in a forward direction.

It is apparent that pawl .45 cannot engage slotted member 44 until thedirection of rotation of sun gear 38 has been reversed in orderto rotatebalk ring 53 out of the way of' the pawl. It is to accelerate thisreversal of rotation that brake 41 is provided.

Brake 41 is preferably located within an adaptor 59 inserted betweenunits I and I6. The brake itself, as stated above, is comprised of acoil 48 fixed to adaptor 59'and an armature 49 splined to intermediateshaft I1. Armature 49 is preferably provided with radial grooves 88which serve partly to increase the unit pressure on the armature andpartly to receive and remove chips or filings which would otherwisescore the surface of the armature. Intermediate armature 49 and coil 48is a friction disc 6| which is shown in partial elevation in Fig. 3.Said 'disc is comprised of a pair of washers 62 and 53 to which isbonded a friction material 64 which is similar to that used on standardfriction clutches- 81 moves from fully closed to approximatelyonequarter open position and is thereafter opened.

The operation of the control circuitis as follows:

- spring 14 but pawl 45 will not move intoengage- Washer 63 is providedwith lugs 65 which extend is shownin detail in Fig. 4. It is comprisedof a an actuating coil 18, a holding coil 1|, an armature 12 and a pawlrod 13 which is connected to armature 12 by means of a spring 14. Aretractile spring 15 normally holds armature 12 and the associated rod13 in retracted position. A switch 18 controls the circuit to theactuating coil 10, a switch 11 controls the usual downshift or kick-downcircuit (not shown) and a third switch 16 controls the effectiveness ofbrake 41.. Switches 16 and 18 are made when pawl 45 is in its retractedposition and break their respective circuits whenthe pawl moves intoengagement with slotted member 44. Switch 15 is completely insulatedfrom its support so that it may be used in series with other switches.

The circuits through the overdrive and brake I are shown in Fig. 7. Abattery 19 or other source of electrical energy is connected on one sideto ground and on the other to a pairof relays 88 and 8| connected inparallel and thence to governor 58 in which is a speed controlled switch82 which may be set to complete a circuit therethrough at approximately23 M. P. H. vehicle speed. Relay 88 is the overdrive relay and isprovidedwith a pair of normally opened contacts 83 which'are adapted toconnect battery 19 with actuating coil 18 and holding coil 1| of theoverdrive electromagnets. Relay 8| is the brake relay and is providedwith a pair of normally opened contacts 84 which when closed completes acircuit from battery 19 through electromagnet 48 of brake 41. In serieswith relay III is the switch 18 which it will be remembered is normallymade and is broken when pawl 45 moves into engagement with slottedmember 44, a throttle operated switch 85 and. a third switch IiIi whichis operated by the movement of shift lever 34 which controls the jawclutch 29 to provide either direct drive or second speed drive. Switch88 is normally closed when jaw clutch 29 is in its second speed positionand is opened when jaw clutch 29 is in direct driveposition. Throttleswitch 85 is normallyclosed when throttle lever Assume that countershaftunit I5 is set for second speed drive and thatthe vehicle is moving atless than 23 M.-P. H. which is the cut-in speed of governor switch'82.Assume also that throttle lever 81 has been moved to more thanone-quarter throttle setting. Under these conditions switches 16, 18 and86 willbe closed and switches 83, 84, 85 and 82 will be opened. When aspeed of 23 M. P. H. is reached, governerswitch 82 will close, there-,by'energizing relay 80 and closing the contacts of switch 83 which in-tum energizes solenoid 10 and holding coil 1|. Armature 12 willcompress ment because shoulder 58 of balk ring 53 obstructs suchmovement. Since throttle switch 85 is open, brake'relay 8| will not beenergized and hence the brake will not be applied. When the operatorreleases accelerator pedal 81 to onequarter throttle setting or less,the engine will tend to slow down and at'the same time switch 85 isclosed which completes the circuit through brake relay 8| and closes thecontacts of switch 84, thereby energizing brake electromagnet 48 toapply the brake. With brake 41 applied, intermediate shaft I1 willimmediately slow down and at some point in the slowing down, a speeddifferential will be established between intermediate shaft l1 andoutput shaft I8 which is such as to cause sun gear 36 to stop and beginto rotate in the opposite direction. When this occurs, balk ring 53 willbe moved in the opposite,direction and shoulder 56 will move out of thepath of pawl 45. The latter having been energized by the compression ofspring 14 will instantly move toward engagement with slotted member 44,and since saidslotted member 44 is rotating slowly in the oppositedirection, pawl 45 will move into the first slot thatpresents itself.The inward movement of pawl 45 causes switch 16 to open its contacts andbreak the circuit through brake relay 8| thereby deenergizin-g thisrelay and its associated brake electromagnet 48. Upon reopening thethrottle by means of pedal 81 switch 85 is again opened but it has nofurther effect upon the circuit until pawl 45 is againwithdrawn toreestablish the circuit through switch 16. The transmission will then bein second overdrive ratio.

'It will be observed that should countershaft unit I5 be conditioned fordirect drive before planetary unit I6 is conditioned for overdrive, theautomatically releasable connection between intermediate shafts l1 andinput shaft I4 is no longer effective and a two-way drive connection isprovided between these shafts by means of jaw clutch 29. Under theseconditions intermediate shaft I1 will be quickly decelerated by theengine because of the connection thereto through clutch I2 and hydrauliccoupling II. Under these conditions therefore, there is'no need for anybraking action to be applied to intermediate shaft I1 in order tofacilitate the engagement of pawl 45 with slotted member 44. For thisreason switch 86 is provided which breaks the circuitthrough brake relay.8| whenever jaw clutch 29 is opsleeve A modification of the brake isshown in Fig. 5. This modification is mounted in an adaptor 59a and isprovided with a coil 48a mounted in a stamping 08 which is welded as at89 to the rear wall of countershaft unit I5. A fixed friction plate 90is mounted between coil 48a and the rear wall and is provided with aconical friction surface 9| on the outer periphery thereof. An armature92 in the form of a stamping is splined to a sleeve 93 which in turn iskeyed to shaft; I'Ia so as to rotate therewith. A spring 94 normallykeeps armature 92 separated from coil 48a. Said armature 92 is flared atits open end 95 to provide a complementary conical surface 96 forconical surface 9| on plate 90. This form of brake may be used where acheaper construction is necessary and considerable holding power isrequired. Another modification of the brake is shown in Fig. 6. Thisform is somewhat similar to the form shown in Fig. 5 but is providedwith a smaller conical friction surface. The brake mechanism is mountedin an adaptor 59b and cooperates with a shaft I'Ib to arrest therotation of the latter. The brake itself is comprised of a coil 48bwhichis mounted in a two-part stamping 91, 98 held in adaptor 59b by ashoulder 99 in said adaptor. The armature is comprised of a flangedwasher I which is held against rotation by one or more pins IOI mountedin adaptor 59b and extending into a slot I02 in washer I00. A conicalfriction surface I03 is provided in washer I00 which cooperates with aconical surface I04 in a I05 keyed to rotate with shaft I'Ib. A springI06 separate conical surfaces I03 and I04 when the brake is deenergized.

It is understood that the modifications shown in Figs. 5 and 6 may beconnected electrically in the circuit shown in Fig. 7 in exactly thesame manner as brake 41.

It is understood that the foregoing description is merely illustrativeof preferred embodiments of this invention andthat th scope of theinvention'therefore is not to be limited thereto but is to be determinedby the appended claims,

I claim:

1. A transmission comprising a driving member, a driven member, anintermediate member, one-way clutching means connecting the intermediatemember to the driving and driven members for a drive from the drivingmember to the driven member through the clutching means and intermediatemember and allowing the intermediate member to float when the drivingmember ceases to drive, a speed changing mechanism for connecting theintermediate member to thedriven member, means responsive to a speeddifferential between the intermediate and driven members for renderingthe speed changing meshanism effective, and means for accelerating theestablishment of the speed differential.

2. A transmission comprising a driving member, a driven member, anintermediate member, one-way clutching means connecting the intermediatememberto the driving and driven members for a drive from the drivingmember to the driven member through the clutching means andintermediate-member and allowing the intermediate member to float whenthe driving member ceases to drive, a speed changing mechanism forconnecting the intermediate member to the driven member, meansresponsive to a speed differential between the intermediate and drivenmembers for rendering the speed changing mechanism effective, and meansacting directly upon the inter-' mediate member for accelerating theestablishment of the speed differential.

3. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive the intermediate member will float, speed changingmechanism for connecting the intermediate member to the driven shaft,means responsive to a predetermined speed differential between theintermediate and driven members for rendering the speed changingmechanism effective, means for accelerating the establishment of thespeed differential, and means controlled by the speed differentialresponsive means for rendering the accelerating means ineffective.

4. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members such that when the driving memberceases to drive the intermediate member will float, a planetarytransmission for connecting the intermediate member to the driven shaft,said transmission having an element which is adapted to be held againstrotation to effect a speed ratio change between the intermediate anddriven members, means responsive to a speed differential between theintermediate and driven members for holding the element againstrotation, and means for accelerating the establishment of the speeddifferential to decrease the amount of time required to arrest therotation of said element.

5. A transmission comprising a driving member, a driven member, anintermediate member, releasable means for connecting the intermediatemember to the driving and driven members such that when thedrivingmember ceases to drive, the intermediate member will float, aplanetary transmission comprising a carrier connected to theintermediate member, a ring gear adapted to be connected to the drivenmember and a sun gear, means for arresting the rotation of the sun gearto drive the driven member at a greater speed than the intermediatemember, said means comprising a slotted element drivingly secured to thesun gear, a radially slidable pawl adapted to engage the slottedelement, the end of said pawl being chamfered to prevent engagement ofthe pawl with a slot except upon a reversal of driving relationstherebetween, and a brake on the intermediate member for slowing downthe carrier in order to accelerate the reversal of driving relationsbetween the pawl and slotted element.

6. A transmission comprising a driving member, a driven member, anintermediate member, an overrunning clutch connecting the intermediatemember to the driving member, an overrunning clutch connecting theintermediate member to the driven member, said overrunning clutchesproviding a drive from the driving member to the driven member throughthe clutches and the intermediate member and allowing the intermediatemember to float when the driving member ceases to drive, a speedchanging mechanism for connecting the intermediate member to the drivenmember, means responsive to a speed differential between theintermediate and driven members for rendering the speed changingmechanism effective, and means acting directly upon the intermediatemember for accelerating the the amount of time required to render thespeed changing mechanism efiective.

7. A transmission comprising a. driving member, a, driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members such that when the driving memberceases to drive, the intermediate member will float, a speed changingmechanism for connecting the intermediate member to the driven member,said speed changing mechanism having a rotatable element the rotation ofwhich is adapted to be arrested to provide a different speed ratio,radially slidable means for arresting the rotation of said rotatableelement, said-radially slidable means being responsive to a speeddifferential between the intermediate and driven members, means actingdirectly upon the intermediate member for accelerating the establishmentof the speed differential, and means controlled by movement of saidradially movable member to operative position to render the acceleratingmeans ineffective.

8. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate mem-.ber to the driving and driven members such that when the driving memberceases to drive the intermediate member will float; a speed changingmechanism for connecting the intermediate member to the driven member,said speed changing mechanism including a rotatable element the rotationof which i adapted to be arrested to provide a different speed ratio,radially slidable means responsive to the speed differential between theintermediate and driven members for arresting the rotation of saidrotatable element, an electrically operated brake on the intermediatemember for accelerating the establishment of the speed differential, anda switch operated by the radiallymovable means for breaking the circuitto the electric brake to render said brake inoperative after theradially slidablemeans has become operative.

9. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive, the intermediate member will float, speed changingmechanism for connecting the intermediate memher to the driven member,means responsive to a speed differential between the intermediate anddriven members for rendering the speed changing mechanism effective, andbrake means for accelcrating the establishment of the speeddifferential, said brake means comprising an electromagnet surroundingthe intermediate member and fixed against rotation relative thereto, anarmature drivingly associated with the intermediate member, means forenergizing the electromagnet and means controlled by the speeddifferential responsive means for deenergizing the magnet.

10. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven member, such that when the driving memberceases to drive the intermediate member will float, speed changingmechanism for connecting the intermediate member to the driven member,means responsive to a speed differential between the intermediate anddriven members for rendering the speed changing mechanism eifective, aspeed controlled switch, and brake means for accelerating theestablishment of the speed difierential, said brake means comprising anelectromagnet surrounding the intermediate member and fixed againstrotation relative thereto, an armature drivingly associated with theintermediate member, means for energizing the electromagnet, meanscontrolled by the speed differential responsive means for deenergizingthe magnet, and mean controlled by the speed-controlled switch forcontrolling the energization of the electromagnet.

- .11. A transmission as described in claim 9, said armature being madeof steel, and an annulus non-rotatably secured to the 'electromagnet andprovided with a friction facing for preventing scoring of the armature.

12. A transmission comprising a driving'shaft, a driven shaft, anintermediate shaft, means including an overrunning clutch for connectingthe intermediate shaft to the driving shaft, an overrunning clutchconnecting the intermediate shaft to the driven shaft, planetary gearingadapted to be connected between the intermediate and driven shafts, saidgearing comprising a planetary gear connected to the intermediate shaft,a ring gear connected to the driven shaft, and a sun gear, means forarresting rotation of the sun gear to provide an overdrive between theintermediate and driven shaft, said last mentioned means comprising aslotted member drivingly associated with the sun gear and a rotationallyfixed radially slidable pawl adapted to engage said slotted member,speed responsive means for controlling the radially slidable pawl, abrake on the intermediate shaft for decelerating the carrier and therebythe sun gear, said decelerating means being speed controlled, and meanson the pawl for rendering the decelerating means ineffective when thepawl is operative to arrest the rotation of the sun gear.

13. A transmission as described in claim 12, said means for controllingthe pawl and said means for decelerating the intermediate shaftcomprising electromagnets and means interconnecting the electromagnetsand speed controlled'means such that the circuit through thedecelerating means is broken either when the pawl is operative, or whenthe speed-controlled means is rotating below a predetermined speed.

14. A transmissioncomprising a driving shaft, a driven shaft, anintermediate shaft, means in-- cluding an overrunning clutch connectingthe in-' termediate shaft to the driving shaft, an overrunning clutchconnecting the intermediate shaft to the driven shaft for direct drive,planetary gearing for establishing an overdrive between the intermediateshaft and driven shaft. said gearing including means for arresting throtation of the sun gear, a brake on the intermediate shaft likewiseeifective to arrest the rotation of the sun gear, speed control meansfor controlling the operation of the brake and the sun gear arrestingmeans, and means on said sun gear arresting means for rendering thebrake means ineffective when the rotation of the sun gear has beenarrested.

e 15. A transmission comprising a drive shaft, a driven shaft, anintermediate shaft, one-way clutching means connecting the intermediateshaft to the drive and driven shafts for a drive from the drive shaft tothe driven shaft through the clutchin means and intermediate shaft andallowing the intermediate shaft to float when the drive shaft ceases todrive, change speed gearing connectible between the intermediate shaftand the driven shaft, positively interengageable elements for effectinga speed ratio change in the change speed gearing, said elements beingengageable upon a reversal of direction of rotation of one of theelements with respect to another of said elements, said one of theelements being associated with the intermediate shaft, and means fordecelerating the intermediate shaft to facilitate the engagement of saidelements.

16. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive,- the intermediate member will float, other meansoperable to connect the intermediate memberto the driving member, saidother means when operated serving to establish a fixed speed relationbetween the intermediate and driving members such that the intermediatemember will not fioat, a speed changing mechanism for connecting theintermediate member to the driven member,

means responsive to a speed differential between the intermediate anddriven members, for renrings, one of said rings being non-rotatablyfixed in the electromagnet, and a friction ring bonded to the coplanarrings.

20. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive, the intermediate member will float, speed changingmechanism for connecting the intermediate member to the driven member,means responsive to a speed differential between the intermediate anddriven members for rendering the speed changing mechanism effective, andbrake means for accelerating the establishment of the speeddifferential, said brake means comprising an electromagnet surroundingthe intermediate member and fixed against rotation relative thereto, and

an armature drivingly associated with the intermediate member, saidelectromagnet comprising a coil coaxial with the intermediate member, anon-rotatable stamping for supporting the coil, a fixed plate having aconical peripheral surface, and said armature having a complementaryconical surface adapted to engage the first-mentioned conical surfaceand being fixed to and rotatable transmission including a control memberresponsive to the speed of the driven member and adapted to render theaccelerating means ineffective except above a predetermined speed of thedriven member.

18. A transmission comprising a driving member, a driven member, anintermediate member, one-way clutching means connecting the intermediatemember to the driving and driven members for a drive from the drivingmember to the driven member through the clutching means and intermediatemember and allowing the intermediate member to float when the drivingmember ceases to drive, speed changing mechanism for connecting theintermediate member to the driven member, means responsive to a speeddifferent-ial between the intermediate and driven members for renderingthe speed changing mechanism effective, and brake means for acceleratingthe establishment of the speed differential, said brake means comprisingan electromagnet surrounding the intermediate member and fixed againstrotation relative thereto, and an armature drivingly associated with theintermediate member.

19. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive, the intermediate member will float, speed changingmechanism for connecting the intermediate member to the driven member,means responsive to a. speed differential between the intermediate anddriven members for rendering the speed changing mechanism effective,brake means for accelerating the establishment of the speeddifferential, said brake means comprising an electromagnet surroundingthe intermediate member and fixed against rotation relative thereto, andan armature drivingly associated with the intermediate member, and afriction ring interposed between the armature and the electromagnet,said ring comprising a plurality of coplanar coaxial with theintermediate member.

21. A transmission comprising a driving member, a driven member, anintermediate member,

releasable means connecting the intermediate member to the driving anddriven members, such that when the driving member ceases to drive, theintermediate member will float, speed changing mechanism for connectingthe intermediate member to the driven member, means responsive to aspeed differential between the intermediate and driven members forrendering the speed changing mechanism effective, and brake means foraccelerating the establishment of the speed differential, said brakemeans comprising an electromagnet surrounding the intermediate memberand fixed against rotation relative thereto, and an armature drivinglyassociated with the intermediate member, said electromagnet having aconical friction surface and said armature comprising a stampingsurrounding the electromagnet and having a conical friction surfaceengageable with the first-mentioned fixed surface, and resilient meansfor-separating the friction surfaces. a

22. A transmission comprising a driving member, a driven member, anintermediate member, releasable means connecting the intermediate memberto the driving and driven members, such that when the driving memberceases to drive, the intermediate member will fioat, speed changingmechanism for connecting the intermediate member to the driven member,means responsive to a speed differential between the intermediate anddriven members for rendering the speed changing mechanism effective, andbrake means for GEORGE E. F'LINN.

